textproduct: Quad Cities

KEY MESSAGES

- Marginal severe risk threat level (1 out of 5) for evening hours.

- Above normal temperatures for the next few days. Today's high temps will be in the upper 80s and low 90s.

- The pattern remains active through the end of the week with precipitation chances of 20-50%

SHORT TERM /THROUGH THURSDAY NIGHT/

Issued at 318 AM CDT Wed Jun 11 2025

Today:

A stalled out boundary along the MN and IA boundary today will lead to rampant warm air advection across the region. Southwesterly flow through the day will produce above normal temperatures in the upper 80s and low 90s. We are still monitoring the potential for severe weather to develop later in the day but the parameter space is looking less favorable then 24 hrs ago. While we will be able to build in some decent instability with MLCAPE values on the order of 1-2k J/kg, thermal profiles show a cap in the lower levels that will inhibit convective development. The cap does decrease a bit the further north you go where we are still carrying PoPs of 20-40% in the evening hours. Based on the latest trends from the CAMs the main show looks to be to our north along the stalled out boundary in northern IA and southern WI. Simulated reflectivity has most of the activity on the northern side of the boundary where the better deep layer shear is present. However, if we do manage to develop some cells south of the boundary the convective parameter space totes some steep low level lapse rates which could produce some damaging winds or some brief hailers.

Thursday:

The aforementioned boundary pushes further north into southern MN on Thursday with the Quad Cities region firmly located in the warm air advection wing of the system. Available moisture will steadily be increasing with PWATs climbing in excess of 1.00" Model soundings do not indicate a capping inversion in place, so through the diurnally heating mechanics we can expect some scattered showers and thunderstorms to develop in the afternoon. Buoyancy in on the low side and bulk shear is weak. As such there is no severe threat expected on Thursday with storms being more of the air mass type.

LONG TERM /FRIDAY THROUGH TUESDAY/

Issued at 318 AM CDT Wed Jun 11 2025

Friday - Extended:

An active pattern is expected through early next week. As an upper level low moves across the Southern Plains before rejoining weakening on Sunday. The air mass overhead does not undergo any meaningful changes until next week as with the stalled out baroclinic zone still dissecting the Upper Midwest. Diurnally driven showers and storms will be common place through the weekend.

The threat for heavy rain has also decreased. While our northern tier of counties are not fully in the clear yet the overall trend has been pulling the larger totals north into southern MN. EFI's for the Quad Cities region has completely dropped off. Mind you we won't be dry, as we continue to carry PoPs of 20-50% through the weekend.

Looking at the 00Z suite of deterministic guidance there isn't a strong consensus as to when the pattern change will arrive. The GFS and the Euro show hints of a larger system moving through the Midwest late Monday. Model run to run consistency is very poor this far out lending itself to low confidence on precipitation chances.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 545 AM CDT Wed Jun 11 2025

VFR conditions through the forecast period. A stalled out surface boundary along the IA and MN border will lead to rampant warm air advection over the region. Southwesterly flow will pour through the terminals through the day with a few gusts in excess of 20 kts in the afternoon. There still remains some uncertainty as to whether we will be able to generate thunderstorms in the afternoon and evening hours. The best chances look to be further north where storms along the boundary may spill southeast in the late afternoon and evening hours. One tricky part for the overnight hours will be wind direction. If storms do manage to drop further south this evening then that would mean the stalled boundary may set up over the Quad Cities region leading to wind directions more out of the east as opposed to the south.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.